I don't really know if anyone still uses an OS that cannot differentiate from uppercase and lowercase charactes. That being said, that part of the packaging guide is probably as old as cube itself. So disregard that, it's more of a tradition to do it like so, not an absolute rule. Besides, aren't we forgetting DM_BS1 in sauer?

Also, you can't load it because of the improper packaging? That sounded lame :P
It's like you said "I won't bother taking a look at this until the .zip conforms to the standards."

Even if OS nowadays support it, uppercase symbols still shouldn't be done (neither anything else than _ or -). Else we eventually get n@M_eS L1%kE tHi$ (Assault Cube suffered this fate which also let people use the lowercase L but also the uppercase I; not a smart idea as only a very few pixels make the difference. Same thing counts for the | or ¡).
Just keep it strict and simple, that's the power of a good name.
The map isn't working in the MyGames directory, so not working to me.

I think that the packaging guide should stay as it is, and that it's worthwhile to try and enforce it. It encourages neat presentation and greatly simplifies installing downloaded maps in Sauer. Removing .DS_Store and other OSX folders, while it might not really make a difference, does help keep things clean.